Denying something that a kid wants to try can cause them to grow up and eat lots of trash. My parents were super zealous about only eating healthy food, we lived on a farm, grew most of our food and raised most of our meat, but we had friends who could eat whatever they wanted, and when we went to their houses, we got to have kudos bars, and other junk. Later in life, when we left the nest and went to college and so forth, all 4 of us had overeating problems. I am the only one who has overcome this, and it is not always easy. I have a sister and a brother who live on junk food, and who, after discussing in depth, acknowledge that it comes from it being so forbidden to us as kids. My younger sister is better at battling it than the other two, and she also acknowledges it as being a problem. I think you have to be pretty delicate with a kid's psyche. I think if they don't visit friends who eat junk, or see the parents eating junk, or see commercials for the junk, then it is probably easier to avoid this problem, but being a child of the 80s/early 90s, even without cable on our farm, I was still inundated with the knowledge that these "delicious" treats were out there.
So I don't really know the answer, or what I will do with my children when we have them someday. Advertising is everywhere and it only gets worse. Our goal is to homeschool, but that doesn't mean they will be holed up and not exposed to this food. I would love to think that they would grow to have no taste for it, but denying food can cause major issues that can lead to finding the food as soon as one is able, hoarding it at time (with my older sister) and secret eating. I don't know if it is better to just provide them with all of the best foods possible, but let them have cake at a friend's birthday party, and hope they don't like it, or how to teach balance. I don't think it is so black and white.